Thanks for the input! I am probably going to use an AMD 6-8 core processor to start with considering that they are realtively cheap and have a good general utility for the cost (of course with an open system design such as test-bench, this can be swapped out on a whim if a more powerful CPU is ever needed for anything). RAM, being one of the cheapest components, I was looking at 8GB minimum which also adds to the multi-use aspect. I will also check out the Corsair you recommend.
That hashcat looks pretty cool, I had not seen that before. I am hoping to get back to BOINC at some point, I would really like to have three to five rigs to cover differing specialties at some point i.e. a miner, HTPC, BOINC, General Use, but that is not happening anytime soon which is why multi-use is important to me.
I personally think it is a mistake to dedicate the unit to tasks other than mining. You will lose efficiency and increase the chances of downtime.
Also, you seem to have mistaken my reason for choosing the APU in my recommended setup: It was because I believed the extra $17 to be worth the extra MH/s the GPU in the APU would give.